From 3a3675b7f23f83ca8c67c9c2b6edf707fd28d1ba Mon Sep 17 00:00:00 2001
From: Dan Rosenberg <drosenberg@vsecurity.com>
Date: Mon, 14 Feb 2011 13:45:28 +0000
Subject: xfs: prevent leaking uninitialized stack memory in FSGEOMETRY_V1
The FSGEOMETRY_V1 ioctl (and its compat equivalent) calls out to
xfs_fs_geometry() with a version number of 3. This code path does not
fill in the logsunit member of the passed xfs_fsop_geom_t, leading to
the leaking of four bytes of uninitialized stack data to potentially
unprivileged callers.
v2 switches to memset() to avoid future issues if structure members
change, on suggestion of Dave Chinner.
Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Reviewed-by: Eugene Teo <eugeneteo@kernel.org>
Signed-off-by: Alex Elder <aelder@sgi.com>
---
fs/xfs/xfs_fsops.c | 3 +++
1 file changed, 3 insertions(+)
(limited to 'fs')
diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
index cec89dd5d7d2..85668efb3e3e 100644
--- a/fs/xfs/xfs_fsops.c
+++ b/fs/xfs/xfs_fsops.c
@@ -53,6 +53,9 @@ xfs_fs_geometry(
xfs_fsop_geom_t *geo,
int new_version)
{
+
+ memset(geo, 0, sizeof(*geo));
+
geo->blocksize = mp->m_sb.sb_blocksize;
geo->rtextsize = mp->m_sb.sb_rextsize;
geo->agblocks = mp->m_sb.sb_agblocks;
--
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